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  <script>
    // 摄氏度 = 5/9.0*(华氏度-32)保留3位小数
    var huashi = 80
    var sheshi = 5 / 9 * (huashi - 32)
    sheshi = sheshi.toFixed(3)
    console.log('80华氏度等于' + sheshi + '摄氏度')
  </script>
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